Improvement in balanced slide-valves



G. WESTINGHOUSE, Jr. Improvement in Balanced Slide-vaives.

No. 131,380. Patented sep.17,1s72.

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ITNESSES. lNVENTOR m. layman/Murillo m/n/vssMf/:S Mauss) UNITED STATES GEORGE WESTINGHOUSE, JR., OF PITTSBRG, PENNSYLVANIA..

IMPROVEMENT IN B ALANcED sLlDE-vALvEs.

Specification forming part of Letters Patent No. 131,380, dated September 17, 1872.

To all whom it may concern:

Be it known that I, GEORGE WEsTING- HOUSE, Jr., of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Balanced Slide-Valves; and I do hereby declare the following to be a full, clear, and exact description thereof, reference being had to the accompanying drawing forming part of this speciiication, in which- Figures 1 and 2 represent, on a plain surface, a longitudinal'sectional elevation of my improved valve with the communicating-ports.

Like letters of reference indicate like parts in each. The desirability of counterbalancing the downward pressure on the ordinary steam-engine slide-valve is well known to those skilled in the art. B y my improvement I accomplish this, and also provide an equal area of steam and exhaust-port openings withr half the or-- dinary movement ofthe valve after such ports begin to open.

To enable others skilled in the art to make and use my improvement, I will proceed to describe its construction and mode of operation.

A represents the exhaust-port of an ordinary steam-engine, and B and B' the ordinary steam-ports which lead from the steam-chest to the opposite ends of the steam-cylinder. To adapt my improvement the better to steamengines which have their port openings in close proximity, I have shown a false bottom, C, which is so constructed as to constitute the bottom of the steam-chest, and bring the portopenings at the desired distance from each other. But this may be used or not, at pleasure. In the construction of new engines it can as well be dispensed with, andthe port-openings made in the bottom of the steam-chest at the desired distance from each other. When it is used, a post, a, is rigidly fastened thereto, and, if it is not used, the post a is cast with the cylinder. On the top of the post a is a plate, b, concave on its upper face, but having at its ends bearing-surfaces b', on which the valve is partly supported. The slide-valveD is made in the usual way, by casting or otherwise, with a hollow chamber, D', of the form, in longitudinal section, of an inverted bellmouth, as shown, though in cross-section it is rectangular or nearly so. It is also open at the top, as at D", but not to the extent of its largest horizontal area, since the two ends project inward over the bell-mouth chamber D' so as to rest, and slide on the ends b' of the plate b. The two ends of the valve are chambered VVor cored out, so as to give auxiliary ports d d',

which lead from the chamber D' to the steamports B B'. In Fig. 1 the steam-port B' is closed and the valve is in proper position for exhausting steam directly from the port B into the chamber D', and indirectly through the auxiliary port d. In Fig. 2 the exhaust is still open to the port B, but the valve is in proper position for taking steam into the port B', both directly from the valve-chamber and indirectly through the port d'.

It will now be obvious that a portion of the pressure is sustained by the exposed upper surface of the plate b, and that with a given constant area of valve-face the pressure on the valve may be decreased or increased by increasing or decreasing the area of the plate b and its exposed upper surface. The amount of bell-mouthed flare will, of course,need to be changed accordingly 5 also, as in some other valves, half the ordinary movement, after a port begins to open, gives the ordinary aggregate area of opening.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. The auxiliary steam and exhaust ports d d', communicating each at one end with a port leading to the end of the cylinder and at the other alternately with the steam and exhaust chambers Or passages, substantially as set forth. Y

2. A slide-valve, D, daring Outwardlyabove its se-at, having an open top, with or without the ports d d', in combination with a supporting-plate, b, substantial1y asand for the purposes set forth.

In testimony whereof I, the said GEORGE 1IVEsTINGrHOUsE, Jr.,have hereunto set my and.

GEORGE VVESTINGHOUSE, JR.

Witnesses:

A. S. N rcHOLsON, G. H. CHRISTY. 

